Multistage internal combustion engine



0d 14, 1941. c. w. P. HEYLANDT ETAL 2,259,308

MULTISTAGE INTERNAL COMBUSTON ENGINE I Filed June 1v,L 1939 Inventors FudaIffe wes Cristzbn Mlelml/U/eyandt *y K E p W A Homey Patented Oct. 14, 1941 MULTISTAGE INTERNAL COMBUSTION ENGINE i Christian Wilhelm Paul Heylandt and Rudolf Mewes, Berlin-Britz, Germany; said Mewes assignor to said Heylandt Application June 17, 1939, Serial No. 279,646 In Germany June 23, 1938 Claims.

This invention relates to that type of multistage internal combustion engine in which a second-stage expansion cylinder is disposed between, and supplied with gases of combustion alternately from, two internal combustion and irststage expansion cylinders.

The invention provides in` an engine of this type a rotary valve common to all three cylinders, yet adapted, as is required, to control the intermediate cylinder in a two-stroke cycle and the others in a four-stroke cycle.

The valve may comprise a head common to the three cylinders and affording a ported cylindrical housing, and a valve member arranged to be rotated in the housing at half engine speed, said valve member having for the two first-stage cylinders fuel inlet passages and burned gas transfer passages each designed to open only passage designed to open twice per revolution of the valve.

Since the operative cycles of the two combustion and first-stage expansion cylinders are necessarily phase displaced by 360 relative to each other, the burnt gas transfer passages in the valve member for the said cylinders are angularly displaced relative to each other by 180. Further, the fuel inlet and the exhaust passages are disposed relative to one another and to said transfer passages to suit the timing of the sequence of operations of the engine.

Preferably each fuel inlet passage extends through the valve member obliquely to its rotational axis, each transfer passage extends within the valve member parallel to the said axis and opens at its two ends tothe periphery of the valve member conveniently in a common axialplane, and the exhaust passage extends diametrically through the valve normal to its axis.

With this preferred arrangement it is possible to provide in the valve housing for each first-stage with each transfer passage and the exhaust passage of the valve member.

By way of example an engine embodying one constructional form of the invention is shown diagrammatically on the accompanying drawing,

to which reference will now be made.

Fig. 1 represents'a fragmentary longitudinal section throughvthe engine with the moving parts vthe speed of the crankshaft.

in one operative position in which the piston in the left cylinder is moving inwardly on a suction stroke, that in the intermediate cylinder is moving outwardly to exhaustcompletely expanded gases, and that in the 'right cylinderis moving inwardly on a firing stroke. l

Fig. 2A is a view similar to Fig. 1 but showing the position of the moving parts after the crankshaft has advanced 180 and accordingly the valve has turned so that the piston in the left cylinder is now moving outwardly on a compression stroke, that in the right cylinder is moving outwardly on a transfer stroke, and that in,

the intermediate cylinder is moving inwardly on a. working stroke by final expansion of the burnt gases so transferred.

`Referring to the figures in greater detail, I

.and 2 denote the two internal combustion and first-stage expansion cylinders, and 3 denotes the second-stage expansion cylinder. II, I2, I3 are the pistons reciprocable in the three cylinders and respectively connected, by connecting rods 2 I, 22, 23, with the crank pins 3|, 32, 33 of a common crankshaft |23. The two crank pins 3|, 32

vare in line and offset from the crank pin 33.

4 is ahead common to the cylinders I, 2, 3 and affording a cylindrical housing for a rotary valve member 5 extending parallel to the crankshaft. This valve member is arranged to be `driven through any suitable gearing (not shown) at half In the housing 4 are interior ports 4I, 42, 43 opening respectively to the cylinders I, 2, 3. The port 4I is adapted to communicate, through a passage 5I in the valve member with an interior fuel intake port 4Ia and, through a transfer passage 5Ia in the valve member,` with the port 43 opening to the cylinder 3. Port 43 serves alternately as interior exhaust port and transfer port. The port 42 is adapted to communicate, through a passage 52 in the valve member, with an interior fuel intake port 42a and, through a transfer passage 52a inthe valve member, with the said port 43. Further, the latter is adapted to communicate, through a passage 53 in the valve member, with an exterior exhaust port 43a.

As shown, the co-acting ports 4I and 4Ia, and similarly the co-acting ports 42 and 42a, are offset axially of the valve 5 while the passages 5I and 52 each extends obliquely through the valve member so that it registers with both of the ports 4I, 4Ia. or 42, 42a .to admit fuel only once during each revolution of the valve, i. e., once during two revolutions of the crankshaft, the valve being rotated at half crankshaft speed as by a posed to open alternately under crankshaft displacement of 360. .Each transfer passage ex- Y.

tends within vthe valve member 5 parallel to its axis andhas its two ends open to the periphery of the valve member as clearly shown in Fig. 2. The exhaust passage 53 extends diametrically through the valve normal to its axis and registers with the co-acting, diametrically opposite ports 43, 43a twice during each revolution of the valve member, i. e. once during each revolution-of the crankshaft.

the valve is adaptedv to control It follows that the two first-stage cylinders l, 2 on a four-stroke cycle and the second-stage cylinder on a twostroke cycle. In practice the fuel inlet passage and the transfer passage foreach rst-stage cylinder are, of course, so dmensioned and relatively disposed as to ensure correct timing of the sequence of the four-stroke'cycle, namely, fuel admission, compression, firing and transfer of the burnt and partially expanded gases to the .intermediate lcylinder.

We claim:

1. A multi-stage internal combustion engine having a two-stroke second-stage expansion cylinder disposed between and supplied with partially expanded burntga'ses alternately from two four-stroke internal combustion and firststage expansion cylinders, valve control means comprising a head common to the three cylinders, a ported cylindrical Yvalve housing in the head, and a valve member rotatable in the housing at half engine speed, said valve member having for the first-stage cylinders fuel inlet passages and burnt gas transfer passages each disposed to open through said housing once per revolution of the valve member and for the second-stage. cylinder an exhaust passage disposed to open through said housing twice per revolution of the valve member, said valve housing revolution of the valve member and for the second-stage cylinder an exhaust passage disposed to open through said housing twice per revolution -of the valve member, said valve housing having for the second-stage cylinder a pair of diametrically aligned ports, and said valve member having a co-acting exhaust passage extending therethrough normal to the valve axis to register with both of said ports twice per revolution of the valve member, a pair of diametrically opposed fuel inlet ports for the first-stage cylinders provided in the valve housing and being offset axially, the fuel inlet passages of the valve member'extending obliquely through its body so as to register with the offset ports when required, one of the aligned exhaust ports of the second-stage cylinder and the fuel inlet ports nearest the first-stage cylinders serving as communicating openings for said transfer passages,

when the latter register with the said exhaust and fuel inlet ports. I.

3. A multitage internal combustion engine having a two-stroke second-stage expansion cylinder disposed between and supplied. with partially expanded burnt gases alternately from two four-stroke internal combustion and first-stage expansion cylinders, valve control means comprising a head common to the three cylinders, a

' ported cylindrical valvehousing in the head, and

a valve member rotatable in the housing at half engine speed, said valve member having for the first-stage cylinders fuel inlet passages and burnt gas transfer passages each disposed to open having for each first-stage cylinder a pair of diametrically opposed fuel inlet ports offset axially of the valve, and said valve member having a coacting fuel inlet passage extending `obliquely therethrough to register with both of said ports only once per revolution of the valve member, transfer and exhaust ports provided in the valve housingfor the second-stage expansion cylinder, and adapted to respectively cooperate with the transfer passages and the exhaust passage provided in the valve member, the inlet ports of the. first-stage cylinders nearest to the cylinder bodies serving as communicating opening for said transfer passages, when the latter register with ,said

inlet ports and said transfer port of the second- Y stage cylinder. 4

2. A multi-stage internal combustion engine. having a two-stroke second-stage expansion cylinder disposed between and supplied with partially expanded burnt gases alternately from. twol four-stroke internal combustionl and firststage expansion cylinders, valve control means comprising ahead common to the three cylinders, a ported cylindrical valve housing in thehead, and a valve member rotatable in the housthrough said housing .once per revolution of the vvalve member and for the second-stage cylinder an exhaust passage disposed to open through said housing twice per revolution of the valve member, said valve' housing having for each firststage cylinder a pair of diametrically opposed fuel inlet ports onset axially of the housing and for the second-stage cylinder a pair of diametrically aligned exhaust ports, and said valve member having two fuel inlet passages extending obliquely therethrough each to register with one of said pairs of fuel inlet ports once per revolution of the valve member and also having an exhaust passage extending therethrough normal to the valve axis to register with the pair of exhaust ports twice per revolution of the valve member, the exhaust port nearest to the second-stage cylinder and the fuel inlet passages nearest to the first-stage cylinders serving as communicating member, when said transfer passages register with one of the said fuel inlet passages and the said exhaust port.

4. In a multi-stage internal combustion engine having a two-stroke second-stage expansion cylinder disposed between and supplied with partially expanded burnt gases alternately from two internaly combustion and first-stage expansion cylinders, valve control means comprising a head common to the three cylinders, a ported cylindrical valve housing in the head extending parallel in'g at half engine speed, said-valve member having/for the first-stage cylinders fuel inlet passages and burnt gas transfer passages each disposed to open through said housing Olite to the engine crankshaft, and a valve member rotatable in the housing at half crankshaft speed, saidv valve member having for' the two'iirst-stage cylinders fuel inlet passages each extending therethrough obliquely to its rotational axis and transfer passages leach extending within the valve member parallel to the said axis and open at its two ends to the periphery of the valve member, and `for the second expansion stage cylinder an exhaust passage extending diametricalper 75,' ly through the valve member normal to its axis,

aasasos said valve housing having a pair of intake ports for each first-stage cylinder, the ports of each pair being oifset relative to each other and comprising exterior and interior ports, the lattter being disposed vadjacent to the iirst-stage cylinders, the oblique inlet passages of the valve member being adapted to register with their respective pairs of oiIset intake ports, an exhaust and a transfer port provided in said valve housing, the exhaust passage of the valve member being adapted to register with the exhaust and transfer ports of the valve housing, when exhaust from the second-stage cylinder is to ltake place, said transfer passages in said valve member being adapted to connect the transfer port with the interior intake ports, when thetransfer of combusted gases from the iirst-stage cylinders into the second-stage cylinder is to take place.

5. In a multi-stage internal combustion engine, a pair of internal combustion andilrst-stage expansion cylinders, a two-stroke second-stage expansion cylinder disposed between and being supplied with partially expanded burnt' gases alternately from said rst-stage cylinders, valve control means common to all three cylinders and comprising a valve housing and a rotary valve member therewithin and disposed parallel to the engine crankshaft; said valve housing being equipped with offset exterior and interior intake ports for each first-stage cylinder, an exterior and an interior exhaust port for the second-stage cylinder, said interior exhaust port and said interior intake ports serving sequentially also as transfer ports; said valve member having intake passages disposed obliquely to its rotational axis and adapted to sequentially register with the said offset intake ports. transfer passages in the valve member arranged parallel to its rotational Yaxis and adapted to sequentially form communications between said interior exhaust port and said interior intake ports, and an exhaust passage passing diametrically 'through the valve member and adapted to sequentially connect said interior and exterior exhaust ports. 

